<!DOCTYPE html>
<html>

<head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
    <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.bundle.min.js"></script> </head>

<body>
    <div class="alert alert-success" role="alert">
        <h4 class="alert-heading">Well done!</h4>
        <p>Aww yeah, you successfully read this important alert
            message. This example text is going to run a bit
            longer so that you can see how spacing within an
            alert works with this kind of content.</p>
        <hr>
        <p class="mb-0">Whenever you need to, be sure to use margin utilities
            to keep things nice and tidy.</p>
    </div>
</body>

</html>